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HP OpenVMS Systemsask the wizard |
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The Question is: This is similar to a question you answered on August 12 - how to you get the OS to write the time back to the TOY clock. I'm faced with the same issue on VMS's realtime cousin, VAXELN, which generates a syntax error for "SET TIME" with no parameters. I realize facility is for VMS questions, but with VAXELN being such an old product, I doubt there are many places to go for answers. If you can't answer the question directly, can you point me in the right direction. In advance, thanks for any assistance you can provide. The Answer is : The Wizard is not particularly familiar with VAXELN. On OpenVMS VAX, the SET TIME command updates saved time value in the SYS.EXE system image. On VAXELN, as the operating system can run diskless, there is not necessarily a corresponding non-volatile location where the time value can be stored -- check your VAXELN documentation for details on non-volatile storage of time. This value saved in SYS.EXE is then added to the VAX TODR (the Time Of Day Register) to determine the current date and time. The VAX TODR has a resolution of roughly 497 days. The 497 day range of the TODR is the reason that a SET TIME command (with no parameters) has to be issued in the first quarter of each calendar year, lest the VAX system time be off when the VAX system finally reboots -- the saved system time in SYS.EXE needs to be updated. Command procedures such as SHUTDOWN will automatically issue the SET TIME command for you. (Alpha systems do not have this particular requirement.) To determine what sort of TOY (Time Of Year) clock is present on the particular system, you will need to check the system processor technical documentation -- if available, you would have to access this value as the saved time value. Alternatively, you could consider establishing a communications link to a server on a remote system (via DECnet or IP) to acquire (and then set) the local system time. NTP would be one approach, though simple DECnet task-to-task might well be the fastest implementation. There are examples of setting the VAXELN system time via a DECnet communications link available via the customer support center.
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